Dusting machine



Oct. 12, 1954 M. H. TUFT nusnuc MACHINE 2 Sheets-Sheet 1 Filed Feb. 5, 1951 Oct. 12, 1954 M. H. TUFT nuswmc MACHINE 2 Sheets$heet 2 Filed Feb. 5,. 1951 I l Iflldfl IIII I I Patented Oct. 12, 1954 DUSTING MACHINE Miles H. Tuft, Huntington Park, Calif., assignor to Hardie Manufacturing Company, Hudson, Mich., ,a corporation of Michigan Application February 5, 1951, Serial No. 209,384

4 Claims.

This invention relates to machines for spreading finely comminuted material such as insecticide dust, and more particularly relates to machines for dusting ground crops with air-borne powders. Because an obviously desirable quality in such machines is ability to cover a wide strip or area in each traverse of a field, and because the density or concentration of the dust cloud at a point distant from the point of initial dustair mixture depends to a large extent upon a smooth velocity gradient between the two points, such machines present problems in coordination of size of the machine and velocity control of the finely comminuted material which it is a general object of this invention to solve.

More specifically, it is an object of this invention to provide a dusting machine capable of dusting a strip of ground extending widely on both sides of the track of the vehicle transporting the machine, and capable of being compacted to a size suitable for road travel, and yet capable of delivering evenly spaced jets on air-borne dust of even concentration across the full Width of the machines traverse. In the attainment of this object, I utilize hollow booms as ducts for the air-dust mixture, these booms being foldable to suitable road positions and being of tapered contruction so as to provide substantially constant velocity for the diminishing volume of the mixture in a manner not practical with flexible extension hoses.

Another object of my invention is to provide a dusting machine of very considerable width which has rigid tubular ducts in which the airdust jets are normally close to the ground to obtain the value of highvelocity impingement f the dust upon the traversed foliage, yet having the ducts mounted to yield to obstructions and to swing automatically back to their operating positions when the obstruction has been passed.

Still a further object of the invention is to provide a dusting machine in which the aforementioned ducts are fed an air-dust mixture in substantially even volume from a central section housing a centrifugal fan which also supplies the area between the ducts with a proportionate volume of the mixture so that even distributionis attained for the full width of the machine.

Further objects and useful advantages of my invention will be pointed out as the following description of a preferred embodiment of my invention proceeds, or will be apparent from the description considered in connection with the accompanying drawings illustrative of that embodiment, in which:

Fig. 1 is a rear elevational view of my improved dusting machine, it being understood that the left-hand boom, shown broken away, is symmetrical with the right-hand boom, and that the machine will normally be mounted upon a tractor or other vehicle providing a source of power, not shown;

Fig. 2 is a bottom plan view, in which both booms are broken away, illustrating the system of jet openings in the under surfaces of the machine;

Fig. 3 is a side elevational view on a slightly enlarged scale, taken from the left of Fig. l; Fig. 4 is a top plan view, on a reduced scale, showing the booms in extended position and, in broken line, in their folded or road-traveling position;

Fig. 5 is a detailed rear elevational and fragmentary view, on further enlarged scale, of the hinge attachment of a left-hand boom, the boom being shown also in its folded position in broken lines;

Fig. 6 is a sectional view on the plane of section 66 of Fig. 5, showing further details of the hinge attachment of the boom, and of gasket sealing means for the hinged joint; and

Fig. 7 is a vertical sectional View on the plane of section 1---'! of Fig. 2, and on an enlarged scale illustrating a preferred arrangement of baffles within the central fan housing, the fan itself being shown in elevation.

Having reference now to the details of the drawings, my improved dusting machine has as its principal components a central casing in housing a centrifugal fan I I to which dust is supplied from a hopper l2, and tubular booms l4 hinged to opposite ends of the casing l6 and normally aligned in the plane in which the fan ll rotates. The entire structure will normally be supported by suitable framework 15 upon a tractor or other vehicle, not shown, having a power take-off for operating the fan II. The hopper l2 and the feed mechanism therefrom to the centrifugal fan ll may be of any type which will provide a substantially constant flow of dust, a suitable type having a convenient method of regulating the dust flow being shown in my co-pending application Serial Number 133,331, filed December 16, 1949. The central casing in with its attached booms [4 will be mounted transversely of the tractor, with the hopper I2 mounted forwardly and connected to the casing in adjacent the shaft ofthe fan I l by a conduit It. The power take-off of the tractor will be connected to a wheel H, from which a belt I 8 drives a wheel 19 mounted on the fan shaft.

Each of the booms IA is attached to the casing H) by a bracket 26 constructed and hinged to permit both rearward and upward motion and consequently a rearwardly and upwardly swing compounded of these motions. The brackets are hinged to the casing It by vertical hinge posts 2l secured to their rearward margins, the posts 2| turning in lugs 22 on the rearward face of the casing Ill. The brackets 29 arch over the upper sides of their respective booms i4 and pivotally support horizontal trunnions 21% on the forward and rearward sides of the booms. The posts 21 and. trunnions 24 form universal joints permitting the aforesaid compound swing in three dimensions. The booms- !4; of course, are hollow to serve as ducts for the air-dust'mixture and at their open inward endsvthey" matewith' openings 25 in the ends of the casing 15. To seal the hollow booms against the perimeters of the openings 25, the booms are provided with large soft'gaskets26; preferably of spongerubber or material of like resiliency, set .incollars 25a which may be secured to the. booms bysuitable reinforcing members 2622, thelatter also securing the trunnions 24 to the booms.

Movementof the-booms Hi "is'limited andcon-- trolled by swinging supports 21. These supportsmaybe cables or rods butmore conveniently are chains which maybe easily adjusted for length. The end plates 28 of'the casing iii, in which the openings 25 occur, are extended=upwardly and braced to the central casing 1| fl by braces 29.. The chain supports 21' aresecured by. bolts 39 to -the upperforward corners of the frames zt -thatis, to. positions. on the frames 28 wellabove the trunnions 2-4 and well forwardly of the hingeposts; 2| upon'which the booms pivotirearwardlyand they aresecured to the booms l lbyiboltsfil well outwardly from thebrackets 20 land are adjusted: in length to permit the boomstoextend horizontally and to seat firmly against the openings 25'; when the booms are-in normal laterally extended operating positions. Towpermittthe chains-Ellisoswing rearwardly withoutobstruction, the-plates. 28 are cut away asshown at 32;

It will be seen thatwhen the booms. [4' swing rearwardlyabout the posts 21,. theywillalso be eonstrained bythe chains 2'l.to pivot upwardlyabout theutrunnions 24, and that the booms-will attain their highest elevation when. they. are pointed rearwardly andthe chains. 2.! pass directlyv over the posts I 21. After: passing: these highpositions thebooms =will.irespond..to gravity to swing to lower anduconvergentpositions as shown in broken lines in Fig. 4:

Because the booms Ilmay. thusbefolded rear.- wardly,,the casing l5.may extendzentirely across. the transporting. vehicle and :still be suitable for. highway. travel. Thus spaceisprovidedfor a large powerful fan and large dustmixing chambers, all in the vertical transverse plane in which the booms operate. The fan; shaft 3.4" extends; through an opening 35;in.the forward, side of-the casing I0, and through an opening35in the rearward side of the casing, where it may be support-r ed on a hanger 31. The openings 35and 36 ad-- mit carrier air to the fan ll, andthe-opening35 also-admits the conduit lfi leading from the hop. per l2. Aguard .38, shown partly broken away; in Fig. l, protects the pulleyssl'liand J5 and the belt I8 and also serves asa stop or-bumper against which the booms I4 may rest when they are folded.

As shown in .Fig. 2, theunder. surfacerof the casing in has openings 40 and the :undensurfaces of the booms [4 have openings 4| for the emission of air-borne dust. To obtain mixture and distribution the casing 10 has a number of interior bafiles, shown in Fig. 7, and may be disposed asymmetrically with respect to the fan I I. Fig. 7 shows the fan H arranged to rotate in a clockwise direction and it will be noted that the endfof'theicasingrlfl towards which the fan blades sweep upwardly is considerably shorter that the opposite end. In the shorter mixing chamber 42, I prefer to provide a plurality of baiiles 43 arranged to deflect the air-dust mixture downwardly toward the openings 40 and outwardly toward the adjacent opening 25, and to incline the upper-plate of-the casing ID, as shown at 44, so that that'portion'of the casing also serves as a directing' surface. In the opposite longer mixing chamber 45 a single downwardly deflecting bafiie 46--and--the inclined upper plate 41 will sufiice to direct the air-dust mixture to the openings 40 and the adjacent opening 25E The: power shaft 48 to: the. driving pulley-.11 isprotected byan in-iner casing i9, from which a short baflle 5fiextends: towards the chamber; 42; A'..lin'etdrawmfrom: the vuppermostibafile' liito the bafflea50 substantially bisects the fan ll; dust quantitydepart'a ing from. the fan to theeleftofisuchxapline and: tothe right thereof Willbe-substantially equal;

To maintain the dust in suspension within the. casing lflLand booms I4, the velocity 0fith8"OaI.== rierair mustbe maintained, despite the lossrofi air through the emission openingsAtl andgfilas; the air proceeds towards theBIldSOithB-bOOIhS; The inclined casing plates H and: 41: diminish: the cross-sectional. area of'the: casing Illrtoward: eachof the openings 25, and. thezbooms Mware tapered from the openings 25. toward their-outerz ends so that the air-dust mixtura-flthough. los:-- ing volume through the emissionopenings; has substantially constant velocity; and. the: pressure at all of the emission openings is substantiallyequal- As heretofore stated, the;bo oms' 4"Wi11 11017 mally be-folded in crossed-position during road.- travel, being then held by gravity in'contactwith. each other or with the guard 38. on other-stop. provided. for the purpose. Theweight of the boomswill prevent-their swaying. or. jostling; When extended to operating positionytheir-weight again holds them in .extendedsposition and-:seals the gaskets 26 against the rims of the-openings 25. If one of the booms encounters'anobstacle, such as a treeor-a .wall, itis free to swing-:rear wardly and at the same timewill swingupwarde ly so as to clear any-low obstruction and: return. quickly to its operating-position. ltmaycnotzbcl forced rearwardly to its highest elevation-from: which .it might swing to its foldedposition .--by. any obstacle which-the; casing. Ill-:wouldclear; When a boom is momentarilymoved rearwardly; some dust willbe-lostat. the unsealediopening 25, but by the use of thick .spongegaskets; 2B the losscan be minimized whenitheswingr-of'thes boom is onlya few degrees; and if the swinga-is v wide; the dust will bea'blowni lIYthEiDlELIIBPIIOI mally occupied bythe boom and generallyndowmward because of the: inclined: plates 44 and; 4

I wish it understoodthat modifications-10fthe: embodiment herein described; withinthe: scope of the appended-claimgare to be consideredcasl included .within the-1 spirit and; scope of". the: inavention.-

I claim-:

1. In. a dusting machine;v a centrifugal: fan'az a source of dust supply arrangedvto'rfeedrdnst'.

to said fan; a casing for said fan elongated in the plane of rotation of said fan and having horizontally directed end openings at levels below the axis of said fan; hollow booms respective to said openings having open ends adapted to seal against said openings to receive dust therefrom, and having downwardly directed orifices for the emission of dust; means pivotally supporting said booms whereby said booms may be moved out of sealing engagement with said end openings; and bafiles within said casing inclined downwardly adjacent to said end openings, Whereby dust emitted from said end openings when said booms are moved therefrom is directed downwardly in like manner to dust emitted from said orifices.

2. In a dusting machine, a casing having an outlet for dust; a hollow boom, having outlets for dust and having an open end mating with said casing outlet to provide a continuous pass sage from said casing to said boom outlets; pivot means supporting said boom on said casing for movement in inclined planes, whereby said boom may swing upwardly and laterally upon encounter with an obstacle and may return to its original position by gravity; and gasket means for sealing said open end of said boom to said casing outlet under gravitational pressure of said boom.

3. In a dusting machine, apparatus as set forth in claim 2, in which said gasket means is of such thickness and resiliency as to continue to seal during small oscillations of said boom.

4. In a dusting machine, a casing having an hinge means for causing said boom to swing concurrently upon both of said hinge means in an upwardly inclined arc; and a thick resilient gasket for sealing said open end of said boom to said casing outlet under gravitational leverage of said boom when said boom is at the lower end of said arc.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 68,112 Rhodes Aug. 27, 1867 486,986 Sohinke Nov. 29, 1892 1,934,718 Knapp et al. Nov. 14, 1933 2,204,099 Allgrun June 11, 1940 2,211,759 Pitner Aug. 20, 1940 2,221,433 Pitner Nov. 12, 1940 2,554,432 Walters May 22, 1951 FOREIGN PATENTS Number Country Date 3,893 Great Britain A. D. 1892 

